PIDTC Administrative Core ? Abstract The Primary Immune Deficiency Treatment Consortium (PIDTC), a member of the Rare Diseases Clinical Research Network (RDCRN), is a Consortium of 44 immunology and hematopoietic stem cell transplant centers throughout the USA and Canada, which was established in 2009 to study rare genetic disorders of the immune system, collectively known as primary immunodeficiency diseases (PIDs). The goals of the PIDTC have been to understand PIDs and define optimal approaches for their definitive treatment. In its first 9 years, the PIDTC has studied outcomes following hematopoietic cell transplantation (HCT), gene therapy (GT) and enzyme replacement therapy (ERT) for patients with severe combined immunodeficiency (SCID), Wiskott- Aldrich syndrome (WAS) and chronic granulomatous disease (CGD). These PIDs are among the most life- threatening, often requiring HCT for survival. However, no single center has followed enough affected individuals to encompass the full spectrum of these disorders. Therefore, a consortium is essential to define the natural history of each PID and multicenter studies are required for robust statistical assessment to compare impacts not only of patient-related variables, but also of treatment-related variables on clinical outcome. Organizing the large number of participating sites and multiple Projects of the PIDTC is a challenge, requiring a carefully crafted administrative structure. The Administrative Core of the PIDTC has been developed to perform the following tasks: 1) overall administration of the PIDTC, including scientific direction and vision, policies, procedures and allocation of funds; 2) integration and supervision of all activities within and among the PIDTC sites, including coordinating communication among the PIDTC sites and bringing together participating investigators into a cohesive PIDTC environment; 3) providing biostatistical support for all PIDTC research, including analysis of data from Projects, Pilots, and inter-Project studies and developing power calculations and study designs for planned initiatives; 4) serving as the point of coordination with the RDCRN, the RDCRN Data Management and Coordinating Center (DMCC) and PID stakeholders and Patient Advocacy Groups (PAGs); 5) production and updates of the PIDTC website and newsletter, both of which serve as our means to broadcast the mission and achievements of the PIDTC, career enhancement opportunities, and awareness of PID and RDCRN-wide resources; 6) participation in RDCRN-wide efforts to develop and disseminate tools and best practices for handling clinical and research data, including the use of Common Data Elements (CDEs), and 7) ensuring a mutually supportive interaction between the scientists conducting clinical research to further the achievement of the goals of the PIDTC. The Administrative Core will continue strengthening and expanding relationships both within and beyond the PIDTC and increasing productivity and services during the next funding cycle.